Try & find a 120Y Borg Warner tailshaft & fit a Series 1 Bluebird 4 speed rear yoke, & get the tailshaft cut to the same length as a 1200 ute length. This will give you removable 25 mm unis that were also used in most Holdens (HQ,etc). The early Bluebird shaft uses the 25mm uni's with a H165 rear pattern. I've used the same combo in a Sunny I do motorkhana's in, didn't trust the standard tailshaft unis & they were the peened in variety anyway. I got the tailshaft from Stewart Wilkins Rallying, he called it the 'green' one, because it's painted green. Already had the Borg Warner tailshaft.